Termination and final pay advice needed please

[w121882]

Hi everyone, my name is Jeff and i have just had my employment terminated. I have been on long term sick just over 2 and a half years now with various illnesses and won a DWP/ESA tribunal last May and signed off for two years. i recently had my 2nd occ health meeting and that went in my favour too. Which has now led my company to terminate my employment. What i would like to know is that i do know i am entitled to holiday pay but is this just this current year or the full 2 and a half years since i have not had any holiday pay for 2014 2015 and so far this year. Any help would be greatly appreciated thanks. Jeff